


Biology Research

by MyKinkIsPapyrus



Series: A First Time for Everyone [3]
Category: Undertale (Video Game)
Genre: Alternate Universe - Inverted Fate, Doctor Kink, Fluff and Smut, Gender-Neutral Pronouns, Loss of Virginity, Other, Reader has a vagina, baculum, because that's the nsfw tag for this au and it's beautiful, dorky code words, inserted fate, kind of but not really
Language: English
Status: Completed
Published: 2019-07-14
Updated: 2019-07-14
Packaged: 2020-06-28 07:30:46
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,894
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/19807594
Author URL: https://archiveofourown.org/users/MyKinkIsPapyrus/pseuds/MyKinkIsPapyrus
Summary: Your lovely skeleton boyfriend and co-worker is the sweetest nerd you've ever met, and you're determined to make sure his first time is a good one.





	Biology Research

You were packing up the notes you had written that day with your monster coworker - a skeleton named Papyrus. He was very enthusiastic about engineering and quantum mechanics. He showed you a portal he made to access alternate universes but told you to keep it a secret for now as he was trying to acquire a patent and better refine the technology. Glancing up, you noticed that very same skelescientist approaching you just as you finished filing away your notes.

“YOU UP FOR THAT BIOLOGY RESEARCH WE DISCUSSED, TONIGHT?” You knew exactly what he meant by that, he was asking if you were free to have sex. When you had been hired a few months back, it quickly became apparent that Papyrus had a crush on you - which you reciprocated. Office romances were not against the rules, but the lead scientist in your shared department was Undyne. After coming to the surface she had been really trying to work out her prejudices against humans but if she found out that you and Papyrus had been dating she probably would have had you transferred to a different team.

So you and Papyrus devised a set of codes. Normal dates would be “cultural studies” and as soon as the topic of eventually having sex came up you both agreed to a code for that as well. Several other people had figured out the two of you were dating - including Papyrus’ brother, Sans - but Undyne had yet to figure it out. According to Papyrus it’s because she’s not very good at recognizing romantic emotions even in herself.

For the past week or so you had both been discussing doing some “collaborative biology research” and you knew it would be his first time so you were determined to make it great for him.

“I’d love to do some biology research tonight, Papyrus.” You smiled at him, a mischievous glint in your eye, his cheekbones darkening just a little. You had also caught on that he might have a kink for using coded scientific terms to talk about sex.

“GREAT! I THINK I HAVE THE EQUIPMENT AT MY HOUSE.”

You filed away your notes and followed him out the door to his car. As soon as you both got in the vehicle you leaned into him before he got a chance to stick his key into the ignition, hand gently rubbing his upper femur through his lab coat. His breath - that he explained he didn't need but practiced doing to keep humans at ease - hitched and stalled at the feeling of your fingers curling around the bone, so close to his pelvis.

“YOU KNOW I CAN'T DRIVE WHEN YOU TOUCH ME LIKE THAT.” He scolded, his voice slightly shaky from anticipation.

“Fine,” you relented but gave him a devious smile. “I'll have plenty of time to...examine...your bones soon.” He seemed to smile a little wider, even more excited than before.

The drive to his house was quick, with each red light you gently teased and fondled him, which he would playfully rebuff just before the light turned green. He pulled into his garage and the instant the car was off and the garage door closed you pounced. With an agility and eagerness he wasn't expecting, you had climbed into his lap, back to the steering wheel. Leaning forward you kissed him excitedly, which he returned with equal energy.

While your lips distracted him, one hand reached down to undo his belt while the other pulled the lever attached to his seat. The sudden decline of the chair caused him to let out a quiet yelp of surprise, which you took as an opportunity to slip your tongue into his mouth.

His hands which had been idle out of surprise until this point moved to action to grab the base of your head in one hand and - much more cautiously - your ass in the other. You moaned a little into his mouth to show your approval of his forwardness. He began to rut his hips a little and you pressed back in response.

He pulled away to moan as you felt his cock form beneath you. Smirking you leaned in to gently kiss his nasal bone.

“I really like how you sound when you're so aroused, Papyrus.” You teased him again by pressing down against the newly summoned appendage, while lightly kissing his cheekbone. You were rewarded with an immediate cry of pleasure from the skeleton, followed just as quickly by an indignant ‘nyeh’.

He responded to your ministrations by strengthening his grip on you, your mouth held to his as he moved his tongue inside, his other hand pressed to your ass, holding it in place as he began to more enthusiastically buck against you. Slowly, your hand slid under his lab coat as the other moved to unbutton it, revealing his spine. Your fingers dragged along the spaces between the vertebrae, drawing another rather loud moan from him.

His response was to slip his hand into your pants to tease your entrance with his finger. He might not have much firsthand experience with the anatomy of anyone but himself, but that doesn't mean he didn't do his research. You huffed quietly at the sensation he was stirring in you.

“I see you did your homework, Doctor Papyrus.” He shuddered intensely at the title, his blush as dark as you've ever seen it.

“YOU KNOW I HAVEN'T OFFICIALLY OBTAINED MY DEGREE YET.” You deviously trailed the hand you had been using to play with his spine into the interior bowl of his pelvis where you moved your fingertips as far into the holes of his sacrum as you could. Your smile more playful as he bit back another languid moan.

“Oh, I know you don't officially have a degree yet, but I also know how much you like it when I call you…” you brought your mouth to the side of his head, just above his flushed cheekbone, “Doctor Papyrus.” His hips seemed to involuntarily thrust upwards as you whispered to where his ear would be.

He fingered you more intensely, causing you to buck your hips to press against his hand and ride his fingers harder. Playfully, you leaned in to press your mouth to his teeth, your other hand sliding to the front of his pants and playing with the summoned bones of his baculum. He had mentioned the fact he had a baculum in a previous conversation you both had had when planning this, and it was one of the most intriguing things he had told you in preparation for having sex with him.

You brought your mouth back to his teeth and kissed him once more, while one hand was busy pulling his cock out of his pants and the other was pulling out a small bottle of lube you had bought (specifically because with a literal bone entering your body, a little extra glide could do anything but hurt). You pulled away and quickly squirted a reasonable amount of lube into your hand before rubbing your hands together and wrapping them both around his bone cock, one hand focused on keeping a mild pace and a firm grip while the other explored more, partially to find his most sensitive spots and partially out of normal scientific curiosity.

You dragged a fingertip around the crevice that separated the vertebrae-like bones, though they lacked the spurs, making them resemble stylized marshmallows almost. He moaned loudly and you smiled at how vocal he was, as you had always enjoyed a vocal man, rare as they tended to be. He seemed to react more extremely to the spaces between the head of his cock and shaft and the space where his shaft connected to his pelvis being massaged.

You thumbed the hole in the head of his cock which made him shout and buck into your hand, so he had that spot in common with most men, which further assured you that you'd be able to show him a good time. You pressed your lips to his skeleton smile again, using it as a distraction to remove your pants as quickly as you can within the confines of the car.

Soon you were naked from the waist down, your lab coat also discarded, and with one hand you positioned his well lubricated baculum below you so it would enter with the least amount of resistance. You looked up to see his face, blushing darkly and mouth slightly agape from what you assumed to be a mix of pleasure and awe.

You made sure to watch his face as you slowly began to sink down onto him, so you could take in every twitch of his mouth, every flutter of his eyes. His breath caught once more and his teeth clicked shut before he hissed out from between his teeth as you sank lower onto his cock. You made it a few inches down before you pulled up and sank down again, the movement helping spread the lube both on him and inside of you. His eyelids fluttered and his head tilted back, one of his hands making its way to your arm and squeezing, while the other, firmly planted on your bare ass, followed suit in squeezing.

He seemed to tremble slightly as you managed to take most of him inside you comfortably, his bones rattling quietly. You leaned forward to kiss him, pulling off of his cock in the process, and you brought your hands to his face to hold while you kissed him and slid back down his baculum. He moaned openly, his teeth clicking together with every breath he took, the air passing between his teeth so harshly it sounded like a hiss.

"Mmm, how are you enjoying the biology research so far, Dr. Papyrus?"

"IT'SSSS G-G-GOING GREAT-T!" He paused to let out a low moan as you continued to ride him. "I HAH-HAVE LEARNED S-SO MUCH." He nearly started sobbing from how close he was. 

The gentle rattling he had been involuntarily doing stopped so suddenly it almost seemed painful as he came into you with a choked gasp and his arms tightened around you. Just as quickly the rattling picked up again, even more intense than before, as he instinctively bucked his hips to ride out his high. Slowly, his shaking calmed and he fell back against his seat, practically boneless despite being nothing but bones.

You gave him a moment as he laid there so motionless he was basically doing a perfect cosplay of an actual corpse. The sight of his usually exuberant self being so wiped out prompted you to laugh a little.

"Oh no, did I kill you?"

He responded, barely coherent, "YEAH YOU MURDERIZED MY VIRGINITY." You snort, your heart warming at what a big doofus he is.

"A true crime of passion. If you've got the energy we should leave the scene of the 'murder' and maybe climb into a different car." He had a blank look on his face before he realized what you meant.

“OH! OOOOOH…” He opened the door to the car, and immediately walked out into the garage, carrying you in his arms while his bacula remained deeply inside you, “OF COURSE!” As he shut the door to the house you could tell the evening was going to be one to remember.


End file.
